U.S. patent number 6,348,058 [Application Number 09/209,248] was granted by the patent office on 2002-02-19 for image guided spinal surgery guide, system, and method for use thereof.
This patent grant is currently assigned to Surgical Navigation Technologies, Inc.. Invention is credited to Joseph Chaudoin, Bradley T. Estes, Kevin T. Foley, Tony Melkent.
United States Patent |
6,348,058 |
Melkent , et al. |
February 19, 2002 |
Image guided spinal surgery guide, system, and method for use
thereof
Abstract
A guide is disclosed for use in performing spinal surgery to
prepare across a spinal disc and adjacent vertebrae an implantation
space. The guide is associated with a computer controlled surgical
navigation system employing an energy-detecting array to track
positions of the guide in three dimensional space relative to a
known reference point. The guide comprises a body for providing
protected access to prepare across the spinal disc and into the
adjacent vertebrae the implantation space. The body has a passage
adapted to receive a bone removal device for forming the
implantation space through the body. At least one electrically
energizable energy emitter array is attached to the body for use in
identifying the location of the guide relative to the adjacent
vertebrae. A system and method for using the guide in spinal
surgery are also disclosed.
Inventors: |
Melkent; Tony (Lafayette,
CO), Foley; Kevin T. (Germantown, TN), Estes; Bradley
T. (Memphis, TN), Chaudoin; Joseph (Germantown, TN) |
Assignee: |
Surgical Navigation Technologies,
Inc. (Broomfield, CO)
|
Family
ID: |
22090010 |
Appl.
No.: |
09/209,248 |
Filed: |
December 10, 1998 |
Current U.S.
Class: |
606/130; 600/429;
606/97; 606/99 |
Current CPC
Class: |
A61B
17/1757 (20130101); A61F 2/4611 (20130101); A61B
34/20 (20160201); A61F 2/442 (20130101); A61F
2/4455 (20130101); A61F 2002/2839 (20130101); A61F
2002/4627 (20130101); A61F 2002/4632 (20130101); Y10S
606/907 (20130101); Y10S 606/909 (20130101); Y10S
606/914 (20130101); Y10S 606/912 (20130101); A61B
2034/2055 (20160201); A61B 2034/2072 (20160201); A61B
2034/254 (20160201); A61B 34/25 (20160201); A61B
2034/107 (20160201) |
Current International
Class: |
A61B
17/16 (20060101); A61B 17/17 (20060101); A61F
2/46 (20060101); A61B 19/00 (20060101); A61F
2/28 (20060101); A61F 2/44 (20060101); A61B
005/05 () |
Field of
Search: |
;606/61,60-66,96-102,129,130,11,80-85 ;600/426,427,429 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 676 178 |
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Oct 1995 |
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EP |
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WO 88/09151 |
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Dec 1988 |
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WO |
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WO 91/04711 |
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Apr 1991 |
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WO |
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WO 91/07726 |
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May 1991 |
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WO |
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WO 92/06645 |
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Apr 1992 |
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WO |
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WO 94/23647 |
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Oct 1994 |
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WO |
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WO 94/24933 |
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Nov 1994 |
|
WO |
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WO96/11624 |
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Apr 1996 |
|
WO |
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WO 97/40764 |
|
Nov 1997 |
|
WO |
|
WO 99/15097 |
|
Apr 1999 |
|
WO |
|
Other References
3-D Digitizing Accessories, Pixsys..
|
Primary Examiner: Reip; David O.
Attorney, Agent or Firm: Harness, Dickey & Pierce,
P.L.C.
Parent Case Text
RELATED APPLICATIONS
This application relies on the benefit of priority of U.S.
provisional patent application Ser. No. 60/069,595, filed on Dec.
12, 1997.
Claims
What is claimed is:
1. A system for use in performing spinal surgery to prepare across
a spinal disc and adjacent vertebrae an implantation space, said
system comprising:
a guide for providing access to prepare the implantation space
across the spinal disc and into the adjacent vertebrae, said guide
having a passage adapted to receive a tool through said guide for
forming the implantation space, said guide having at least one
emitter array attached thereto for use in identifying the location
of said guide relative to the adjacent vertebrae;
a computer controlled surgical navigation system employing an
energy detecting array to track positions of said guide in three
dimensional space relative to a known reference point;
an inserter sized for passage through said guide, said inserter
having at least one emitter array attached thereto for use in
identifying the location of said inserter relative to the adjacent
vertebrae, said inserter adapted to hold one of an artificial
implant and a bone dowel for insertion into the implantation space;
and
wherein said computer controlled surgical navigation system tracks
the position of said inserter in a three dimensional space relative
to a known reference point, and said computer controlled surgical
navigation system generates a display of the position of said
inserter; and
wherein said computer controlled surgical navigation system
displays one of an artificial implant and a bone dowel on the end
of said inserter based on the geometrical configuration of said
inserter and of the one of the artificial implant and a bone dowel
attached to said inserter being entered into said computer
controlled system.
2. The system of claim 1, wherein said emitter array includes at
least one LED.
3. The system of claim 1, wherein said emitter array is an
electrically energizable energy emitter array.
4. The system of claim 1, wherein said emitter array emits
reflective signals.
5. The system of claim 1, wherein said emitter extends to the side
of said guide to provide a line of sight from said emitter to the
energy-detecting array of the navigation system.
6. The system of claim 1, wherein said guide comprises a hollow
tube.
7. The system of claim 6, wherein said hollow tube has a
rectangular cross-section.
8. The system of claim 6, wherein said guide further comprises
spikes for engaging the adjacent vertebrae to inhibit displacement
of the adjacent vertebrae during preparation of the implantation
space.
9. The system of claim 1, wherein said guide has an end including
extensions for penetrating the spine.
10. The system of claim 1, wherein said guide further comprises a
disc penetrating extension extending from said guide for insertion
into the disc space between the adjacent vertebrae and for bearing
against endplates of the adjacent vertebrae.
11. The system of claim 1, further comprising said tool, wherein
said tool has an energy emitter for use in identifying the depth of
penetration of said tool through said guide.
12. A method for performing spinal surgery with a guide used to
provide protected access across a spinal disc and into adjacent
vertebrae to prepare an implantation space, said method
comprising:
contacting one end of said guide having at least one emitter array
attached thereto to the adjacent vertebrae;
employing a surgical navigation system with a computer controller
and a digitizer array for communicating with said emitter array of
said guide;
positioning said guide in three dimensional space relative to a
known reference point;
forming the implantation space through said guide across the disc
space and into a portion of each of the adjacent vertebrae;
implanting one of an artificial implant and a bone dowel into the
implantation space;
providing an inserter sized for passage through said guide, said
inserter having at least one emitter array attached thereto for use
in identifying the location of said inserter relative to the
adjacent vertebrae, said inserter adapted to hold one of an
artificial implant and a bone dowel for insertion into the
implantation space; and
generating a display of the position of said inserter relative to
the adjacent vertebrae to provide a view of the axial orientation
of said inserter relative to the adjacent vertebrae;
wherein the generating displays one of an artificial implant and a
bone dowel on the end of said inserter.
13. The method of claim 12, wherein the contacting includes
contacting one end of a tubular member having at least one emitter
array attached thereto to the adjacent vertebrae.
14. The method of claim 12, wherein the positioning includes the
step of positioning said guide in three dimensional space relative
to a known reference point in the adjacent vertebrae.
15. The method of claim 12, further comprising positioning into the
disc space between the adjacent vertebrae said guide having an
extension for insertion into the disc space and for bearing against
end plates of the adjacent vertebrae.
16. The method of claim 12, further comprising generating a display
of the position of said guide.
17. The method of claim 16, wherein the generating displays the
location of said guide relative to the adjacent vertebrae to
provide a view of the axial orientation of said guide relative to
each vertebra.
18. The method of claim 16, wherein the generating displays the
location of said guide relative to the adjacent vertebrae to
provide a view of the axial orientation of said guide relative the
adjacent vertebrae.
19. The method of claim 16, wherein the generating displays the
location of said guide relative to the adjacent vertebrae to
provide a cross-sectional view of said guide relative to one of an
anterior or posterior view of the adjacent vertebrae.
20. The method of claim 12, further comprising emitting a signal
from said emitter attached to said guide which is received by an
apparatus representatively indicating that signal on a visual
display.
21. The method of claim 12, further comprising reflecting a signal
from said emitter attached to said guide which is received by an
apparatus representatively indicating that signal on a visual
display.
22. The method of claim 12, wherein forming the implantation space
includes passing a tool having an energy emitter through said
guide.
Description
FIELD OF THE INVENTION
The present invention relates generally to providing a guide for
use in performing spinal surgery, in conjunction with systems that
use and generate images during medical and surgical procedures,
which images assist in executing the procedures and indicate the
relative position of various body parts and surgical instruments.
In particular the invention relates to a guide, and system and
method utilizing the guide, for performing spinal surgery to
provide protected access across a spinal disc and into adjacent
vertebrae to prepare an implantation space so as to ensure
predetermined trajectory and placement of an artificial
implant/bone dowel into the implantation space.
BACKGROUND OF THE INVENTION
Various instruments and methods have been used to prepare adjacent
vertebrae of the spine for insertion of a bone dowel or artificial
implant. These instruments and methods allow for the removal of
disc material from between adjacent vertebrae as well as a portion
of each vertebra to form an implantation space or opening. Drill
sleeve, tubular member, sheath, working channel, and guard are a
few of the names for the protective guide used to guide drills and
other disc and bone removal devices into the spine to form the
implantation space for receipt of the bone dowel or artificial
implant. Certain of the guides have a sharpened end or include
teeth for engaging the vertebrae upon application of an impaction
force. The guide can be positioned so as to span the disc space and
be seated into the adjacent vertebrae to provide protected access
to the spine during the process of forming the implantation space.
The implantation space spans the disc space and protrudes into each
of the adjacent vertebrae along two opposed resected arcs. An
example of the procedure for drilling holes across a disc space and
instrumentation pertaining thereto are described in U.S. Pat. No.
5,484,437 to Michelson and is incorporated herein by reference.
The use of cylindrical implants is desirable because the surgeon
can prepare the recipient site by drilling a cylindrical hole
across the disc space and into the adjacent vertebrae. The curved
surface of the cylindrical holes drilled into the vertebrae provide
for the possibility of tight congruency when the cylindrical hole
is fitted with an implant having corresponding cylindrical portions
of matched diameter.
Typically, threaded artificial implants, such as the implant
disclosed in U.S. Pat. No. 5,015,247 to Michelson, the entire
disclosure of which is incorporated herein by reference, are placed
into the implantation space between the adjacent vertebrae to
directly participate and be incorporated in the ensuing fusion.
Threaded bone dowels, such as those taught by Viche may also be
placed into the implantation space for the purpose of bridging the
opening and to be incorporated into the fusion between the
vertebrae. Moreover, artificial implants of the push-in type, such
as those disclosed in U.S. Pat. No. 5,593,409 to Michelson and
assigned to the assignee of the present application and
incorporated herein by reference, may also be inserted into the
implantation space formed by the above described instruments and
methods.
Whether pushing or threading an implant or dowel into the
implantation space, the surgeon attempts to orient the sheath for
guiding the formation of the implantation space to remove
approximately the same amount of material from each of the
vertebra. Once the implant or dowel is implanted, a fluoroscope may
be used to assist in determining if proper placement has
occurred.
A number of different types of surgical navigation systems have
been described that include indications of the relative positions
of medical instruments and body parts used in medical or surgical
procedures. For example, U.S. Pat. No. 5,383,454 to Bucholz; PCT
Application No. PCT/US94/04530 (Publication No. WO 94/24933) to
Bucholz; and PCT Application No. PCT/US95/12894 (Publication No. WO
96/11624) to Bucholz et al., the entire disclosures of which are
incorporated herein by reference, disclose systems for use during a
medical or surgical procedure using scans generated by a scanner
prior to the procedure. Surgical navigation systems typically
include tracking means such as for example an LED array on the body
part, emitters on the medical instruments, a digitizer to track the
positions of the body part and the instruments, and a display for
the position of an instrument used in a medical procedure relative
to a body part.
Procedures for preparing an implantation space in the spine present
certain particular challenges to be addressed at specific levels
within the spinal column. For example, preforming such a procedure
at L4-5 of the spine can raise the following issues: 1) During a
posterior approach, significant muscle stripping and tearing is
required to reach the L4-5 disc space. Significant post-operative
trauma to the patient may result. 2) During an anterior approach,
with either a transperitoneal or retroperitoneal, open or
laparoscopic approach to the L4-5 disc space, the great vessels lie
almost directly on the front of the spinal column at that level.
Dissection and manipulation of these vessels may be time-consuming
and difficult.
The applicant determined that a retroperitoneal "oblique approach"
to the L-5 disc space can present a preferred surgical solution.
The muscle splitting and tearing of the posterior approach is
therefore not inevitable, since the oblique approach takes place
just anterior to the psoas muscle located laterally along the
vertebral column. The oblique approach also allows for an approach
slightly posterior of the great vessels lying anterior on the
spinal column, thus reducing any risk of injury to the great
vessels.
In viewing the spine solely from a lateral fluoro image, the spine
surgeon, via this oblique approach, would have a limited ability to
see an indication of the depth and direction of their
instrumentation as it moves in a posterior lateral fashion across
the disc space towards the exiting nerve root.
In light of the foregoing, it would be beneficial in the art for a
system and method for the placement of a guide in the spine that
provides directional assistance to the surgeon to improve the
placement of the guide used in forming the implantation space as
well as for use in determining the depth of insertion of
instruments passing through the guide, thereby improving the
placement of implants and dowels into the implantation space.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a guide, system,
and method for using the guide in performing spinal surgery to
prepare an implantation space across a spinal disc and adjacent
vertebrae. More specifically, one object of the present invention
is directed to apparatus and procedures for the placement of a
guide into the spine using image guided surgery to improve proper
placement of the guide through which the implantation space is to
be formed and thus proper placement of the implant or dowel.
To achieve this object and other advantages and in accordance with
the purpose of the invention, as embodied and broadly described
herein, the invention includes a guide for use in performing spinal
surgery to prepare an implantation space across a spinal disc and
adjacent vertebrae. The guide is used in conjunction with a
computer controlled surgical navigation system employing an
energy-detecting array to track positions of the guide in three
dimensional space relative to a known reference point. The guide
comprises a body for providing protected access to prepare the
implantation space across the spinal disc and into the adjacent
vertebrae. The body has a passage adapted to receive a bone removal
device for forming the implantation space through the body. At
least one emitter array is attached to the body for use in
identifying the location of the guide relative to the adjacent
vertebrae.
The guide may additionally include a disc penetrating extension
extending from the body for insertion into the disc space between
the adjacent vertebrae and for bearing against endplates of the
adjacent vertebrae. A preferred body includes a hollow tube having
an end including extensions for penetrating the spine. An emitter
array is preferably on each extension of the guide and more
preferably includes at least one LED. Preferred arrays include an
electrically energizable energy emitter array, known as an active
emitter, as well as a reflective surface that reflects signals,
known as a passive emitter.
Additionally, the invention includes a system for use in performing
spinal surgery to prepare across a spinal disc and adjacent
vertebrae an implantation space. The system comprises the above
described guide and a computer controlled surgical navigation
system employing an energy detecting array to track positions of
the guide in three dimensional space relative to a known reference
point.
In addition, the invention further comprises a method for
performing spinal surgery with a guide used to provide protected
access across a spinal disc and into adjacent vertebrae to prepare
an implantation space. The method comprises the steps of: attaching
a reference array to the vertebrae of interest; registering the
location of that vertebrae with a computer controlled surgical
navigation system; contacting one end of the guide having at least
one emitter array attached thereto to the adjacent vertebrae;
employing the surgical navigation system with a computer controller
and a digitizer array for communicating with the energy emitter of
the guide; positioning the guide in three dimensional space
relative to a known reference point system; and forming the
implantation space through the guide across the disc space and into
a portion of each of the adjacent vertebrae.
In another aspect, the method includes the step of generating a
display of the position of the guide. The generating step
preferably displays the location of the guide relative to the
adjacent vertebrae to provide a view of the axial orientation of
the guide relative to each vertebra and/or relative to the adjacent
vertebrae. The orientation of the disc penetrating extensions can
also be displayed. The location of the tip of an instrument which
is placed through the guide can be displayed as well. Identifying
the location of the instrument tip passing through the guide
permits tracking of tool depth insertion. The generating step may
also display the location of the guide relative to the adjacent
vertebrae to provide a cross-sectional view of the guide relative
to one of an anterior or posterior view of the adjacent
vertebrae.
The method may also include the step of emitting a signal from an
emitter attached to the guide which is received by an apparatus
representatively indicating that signal on a visual display. A
preferred method of the present invention also includes the step of
implanting an artificial implant, a bone dowel, or other type of
bone into the implantation space. The method also may include the
step of tracking an artificial implant or bone dowel inserter via
an emitter array attached to the inserter. The inserter preferably
is configured to pass through the guide. The computer controlled
surgical navigation system may be configured to display the
inserter as it passes through the guide and more preferably may
display both the inserter and the attached artificial implant or
bone dowel based on the geometrical configuration of the inserter
and of an implant or bone dowel attached thereto.
The objects of the invention are to provide a surgeon with the
guide, system, and method to track the guide used in conjunction
with a surgical navigation system in such a manner to operate on a
patient on the spine to ensure proper orientation of the guide to
the spine when forming an implantation space.
Additional objects and advantages of the invention will be set
forth in part in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The objects and advantages of the invention will be
realized and attained by means of the elements and combinations
particularly pointed out in this description.
It is to be understood that both the foregoing general description
and the following detailed description are exemplary and
explanatory only and are not restrictive of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute
a part of this specification, illustrate one embodiment of the
invention and together with the description, serve to explain the
principles of the invention.
FIG. 1 is a schematic diagram of one preferred embodiment of a
system, including a guide, a reference arc, a post, and wires
placed in the spine for use with a surgical navigation system for
spinal surgical procedures;
FIG. 2 is a perspective view of one preferred embodiment of a guide
according to the present invention;
FIG. 3 is a perspective view of the guide of FIG. 2 with an
instrument having an LED passing through the guide;
FIG. 4A is a cross-sectional view of a spinal segment having an
implant or dowel in a desirable position within the disc space and
vertebral endplates;
FIG. 4B is a cross-sectional view of a spinal segment having an
implant or dowel in a generally less desirable position within the
disc space and vertebral endplates;
FIG. 5A is a cross-sectional view of an implant or dowel projected
over an axial top view of a vertebra and showing a predetermined
axial alignment of the implant or dowel to the vertebra;
FIG. 5B is a cross-sectional view of an implant or dowel positioned
between adjacent vertebrae and showing a predetermined sagittal
alignment of the implant or dowel to the vertebrae;
FIG. 5C is a cross-sectional view of an implant or dowel positioned
between adjacent vertebrae and showing a predetermined coronal
alignment of the implant or dowel to the vertebrae;
FIG. 6A depicts an image on a display screen produced in
association with the guide, reamer passing through the guide, and
surgical navigation system in accordance with a preferred
embodiment of the present invention;
FIG. 6B depicts the embodiment of FIG. 6A with the reamer inserted
deeper into the spine intervertebral disc space;
FIG. 7 depicts an image on a display screen produced in association
with the guide, a tap passing through the guide, and surgical
navigation system in accordance with another preferred embodiment
of the present invention;
FIG. 8 depicts an image on a display screen produced in association
with the guide, an implant passing through the guide, and surgical
navigation system of yet another preferred embodiment of the
present invention;
FIG. 9 is a side view of a distractor and T-handle assembly with
attached emitter in cross-section;
FIG. 10 is a side view of a guide having a disc penetrating
extension and prong for engaging the adjacent vertebrae with
attached emitter in cross-section;
FIG. 11A is a side view of a tap;
FIG. 11B is a side view of a T-handle with emitter; and
FIG. 12 is a side view of an inserter with attached T-handle and
emitter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred
embodiment of the invention, an example of which is illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings to refer to the same
or like parts. The following example is intended to be purely
exemplary of the invention.
As generally described in PCT/US95/12894, the entire disclosure of
which is incorporated herein by reference, a typical surgical
navigation system is shown in FIG. 1. A computer assisted image
guided surgery system, indicated generally at 10, generates an
image for display on a monitor 106 representing the position of one
or more body elements, such as spinal elements fixedly held in a
stabilizing frame or device such as a spinal surgery frame 125
commonly used for spinal surgery. A reference arc 120 bearing
tracking means such as for example LED emitters 122 is mounted to
the spinous process by a clamp or other connecting device. The
image is generated from an image data set, usually generated
preoperatively by a CAT scanner for example, which image has
reference points for at least one body element, such as a spinal
element. The reference points of the particular body element have a
fixed spatial relation to the particular body element. The system
includes an apparatus such as a digitizer or other Position Sensing
Unit (PSU), such as for example sensor array 110 on support 112 for
identifying, during the procedure, the relative position of each of
the reference points to be displayed by tracking the position of
emitters 122 on arc 120. The system also includes a processor 114
such as a PC or other suitable workstation processor associated
with controller 108 for modifying the image data set according to
the identified relative position of each of the reference points
during the procedure, as identified by array 110. The processor 114
can then, for example, generate a displaced image data set
representing the position of the body elements during the procedure
for display on monitor 106. In summary, the operation of a surgical
navigating system is well known in the art and need not further be
described here.
An embodiment of the present invention permits tracking without use
of a clamp or other connecting device holding an emitter to a
vertebral body by use of dynamic referencing (e.g. fluoroscopy
referencing, magnetic resonance imaging intraoperatively, and
ultrasonic registration). All of these options will show real time
displacement and manipulation of the spine.
In accordance with the preferred embodiment of the present
invention, with further reference to FIGS. 2 and 3, the invention
includes guide 130 for use in performing spinal surgery to prepare
across a spinal disc and adjacent vertebrae an implantation space.
Guide 130 is used in conjunction with computer controlled surgical
navigation system 10 employing energy-detecting array 110 to track
positions of guide 130 in three dimensional space relative to a
known reference point. Guide 130 comprises body 132 for providing
protected access to prepare the implantation space across the
spinal disc and into the adjacent vertebrae. Body 132 has a passage
adapted to receive a bone removal device, as shown in FIG. 3, for
forming the implantation space through body 132. At least one
emitter array 190 is attached to body 132 for use in identifying
the location of guide 130 relative to the adjacent vertebrae. FIG.
10 shows an alternative guide 130 with disc penetrating extensions
134 and attached emitter array 190.
A preferred bone removal device includes a reamer 300 having a LED
310 as shown in FIGS. 3, 6A, and 6B. A visual display of the reamer
300 may be generated showing the depth of insertion of the reamer
300 into the spine relative to the known coordinates of the guide
130 and the body into which reamer 300 penetrates.
Other devices for use in performing spinal surgery across the disc
space are shown FIGS. 9, 11A, 11B, and 12. FIG. 9 depicts a
distractor 410 with attached T-handle 430 and emitter 190. FIG. 11A
shows a tap 400 which is preferably adapted for attachment to
T-handle 430 shown in FIG. 11B. T-handle 430 includes an emitter
190 attached thereto for use in identifying the location of tap 400
relative to the adjacent vertebrae into which it is inserted. FIG.
12 shows an inserter 420 with attached T-handle 430 and emitter
array 190. Emitter 190 on distractor 410, tap 400, and inserter
420, respectively is used to identify the location of each tool in
three dimensional space relative to a known reference point so that
each may be individually shown on the visual display associated
with computer controlled surgical navigation system 10.
Guide 130 may additionally include a disc penetrating extension
extending from body 132 for insertion into the disc space between
the adjacent vertebrae and for bearing against endplates of the
adjacent vertebrae. A preferred body 132 includes a hollow tube
having an end including extensions 134 for penetrating the spine. A
preferred emitter array 190 on the guide are light emitting diodes
("LEDs"), but can be any other energy radiating device or tracking
means known in the art capable of being tracked by a corresponding
detector array. A preferred emitter array includes three LEDs for
use in determining location and rotation of a tool in space in all
directions. For purposes of illustration, not limitation, the
tracking means may generate signals actively such as with acoustic,
magnetic, electromagnetic, radiologic, and micropulsed radar
systems, or passively such as with reflective surfaces.
Additionally, the invention includes a system for use in performing
spinal surgery to prepare across a spinal disc and adjacent
vertebrae an implantation space. The system comprises the above
described guide 130 and computer controlled surgical navigation
system 10 employing an energy detecting array 110 to track
positions of guide 130 in three dimensional space relative to a
known reference point in a body similarly tracked by sensor array
110.
Guide 130 and computer controlled surgical navigation system 10
enable the spine surgeon to ensure the proper implantation of an
implant or dowel by forming a properly oriented implantation space
through guide 130 and into the spine as well as observe the depth
of invention of instruments passing through guide 130. This outcome
is ensured by properly orienting guide 130 prior to forming the
implantation space. FIG. 4A shows a cross-sectional view of a
spinal segment 200 having an implant or dowel 202 in a
predetermined endplate 204 engagement. Typically, the preferred
predetermined endplate 204 engagement occurs when approximately
equal amounts of bone are removed from each of the adjacent
endplates 204 of the adjacent vertebrae and the implant or dowel
202 is axially aligned from anterior A to posterior P or vise
versa.
A cross-sectional view of a spinal segment having an implant or
dowel 202 in a generally less desirable position is shown in FIG.
4B. The implant or dowel 202 depicted in FIG. 4B is shown implanted
in an implantation space having an angled sagittal trajectory. In
contrast, a generally preferred predetermined sagittal alignment of
the implant or dowel 202 to the vertebrae is shown in FIG. 5B.
FIG. 5A shows a cross-sectional view of an implant or dowel 202
projected over an axial section of a vertebra and showing a
predetermined axial alignment of the implant or dowel 202 to the
vertebra from the posterior to the anterior. FIG. 5C is a
cross-sectional view of an implant or dowel 202 positioned between
adjacent vertebrae and showing a predetermined coronal alignment of
the implant or dowel 202 to the vertebra. The proper placement of
guide 130 prior to forming the implantation space enables the
implant 202 to be placed in a predetermined axial, sagittal, and
coronal orientation as depicted in FIGS. 5A, 5B, and 5C.
Once the surgeon registers the vertebral body with computer
controlled surgical navigation system 10, the location of the above
disclosed guide 130 can be viewed on the computer system relative
to that body so that the spine surgeon can see in real time the
location of the end of guide 130 in an axial, coronal, and sagittal
view, as well as in a 3-D reconstruction. The surgeon will also be
able to view the trajectory of guide 130 relative to this body in
all three places. This technique clearly enhances the process for
the surgeon to position guide 130 to form an implantation space and
thereby optimize the positioning of the implant or dowel to be
inserted.
In accordance with the display screens depicted in FIGS. 6A, 6B, 7,
and 8, once a reference array is attached to the patient and
registered, software within navigational system 10 provides the
following information to the surgeon. The location of guide 130 is
shown relative to the anatomy of the patient. The rotational
position of guide 130 is also indicated to allow the surgeon to
observe the orientation of guard extensions 134 relative to the
adjacent vertebrae of the spine.
In particular, FIGS. 6A and 6B display reamer 300 inserted through
guide 130 and show the depth of penetration of reamer 300. FIG. 6A
shows reamer 300 just prior to removing material from the vertebrae
endplates. FIG. 6B shows reamer 300 at a greater depth of insertion
and after removal of material from the vertebrae endplates. The
final position of reamer 300 remains on the display screen for
reference by the surgeon. The diameter of the reamer 300 is
preferably entered into the computer or selected from a programmed
menu.
FIG. 7 depicts tap 400 being inserted through guide 130. The final
position of tap 400 remains on the screen for reference by the
surgeon. The diameter of tap 400 is entered into the computer or
selected from a programmed menu.
FIG. 8 shows a display representing the location and depth of
implant 500 after insertion through guide 130. The final position
of implant 500 remains on the screen for reference by the surgeon.
Both the tip and tail of implant 500 is visible on the screen. The
diameter and length of implant 500 is preferably entered into the
computer or selected from a programmed menu.
By entering the dimensions of implant 500 into the computer or by
selecting an implant size from a programmed menu and by having the
geometric configuration of inserter 420 in the computer, the
display can show the implant in relation to the adjacent vertebrae
by knowing the position of the inserter and thereby knowing the
position of a rigidly attached implant 500. In this manner, one can
keep track of implant 500 or any other device of known dimension
attached to a tool of known dimension having an emitter array
attached thereto. By providing an emitter array on a tool of know
dimension and tracking its position, the position of another device
of known dimension rigidly attached to the tool can also be
determined with certainty. Thus, the implant or other device can be
displayed on the navigation system monitor without need for a
separate emitter on the attached device.
Having described the preferred embodiment of the guide used in the
present system, the method of using this apparatus to practice the
invention will now be described. The operation of a surgical
navigating system is generally well known and is described in
PCT/US95/12894. The first step is to identify the location of the
spine using computer-aided image guided surgical navigation
methods.
A reference array 120 is rigidly attached to the vertebrae of
interest. The attachment means can be a clamp, screw, or any other
means. The reference array can be attached to a spinous process,
for example, in a posterior case or to the anterior body in an
anterior case. The array can be mounted percutaneously from a
minimally invasive technique. Once the reference array is attached,
the body of interest must be registered to the image data in the
computer controlled surgical navigation system. This can be
accomplished in many different ways. In an open or endoscopic case,
points on the bone can be physically touched with a tracked
pointer. For a percutaneous technique, points on a fiducial array
which was attached to the body before the scan can be touched, or
points on Fluoroscopic or Ultrasonic images can be identified. The
invention may be used with any registration technique. The
invention may also be used with any surgical technique (i.e.
posterior, anterior, laparoscopic, anterior endoscopic, etc.)
Once the reference 120 is placed on the patient and the anatomy is
registered with the computer system, guide 130 can be tracked in
space relative to the spine in the surgical navigation system
without further surgical exposure of the spine. The position of
guide 130 is determined by the user stepping on a foot pedal 116 to
energize the emitter array 190. The emitters 195 generate infrared
signals to be picked up by camera digitizer array 110 and
triangulated to determine the position of guide 130. The relative
position of the body part, such as the spinal process is determined
in a similar manner, through the use of similar emitters 122
mounted on the reference frame 120 in mechanical communication with
the spinal segment. As is well known in this art and described in
PCT/US95/12894, based upon the relative position of the spinal
segment and guide 130 (such as by touching a known reference point)
the computer would illustrate a preoperative scan--such as the
proper CAT scan slice--on the screen of monitor 106 which would
indicate the position of guide 130 and the spinal segment. It is
also understood that passive as well as active tracking techniques
can be used throughout.
After the spinal elements are registered in the spine, a guide can
be properly oriented so that disc and bone may be removed through
the guide to form a properly oriented implantation space into which
an artificial implant or bone dowel may be inserted.
In addition, the invention further comprises a method for
performing spinal surgery with a guide used to provide protected
access across a spinal disc and into adjacent vertebrae to prepare
an implantation space. The method comprises the following steps:
contacting one end of the guide having at least one electrically
energizable energy emitter array attached thereto to the adjacent
vertebra; employing a surgical navigation system with a computer
controller and a digitizer array for communicating with the energy
emitter of the guide; positioning the guide in three dimensional
space relative to a known reference point; and forming the
implantation space through the guide across the disc space and into
a portion of each of the adjacent vertebrae.
In another aspect, the method includes, the step of generating a
display of the position of the guide. The generating step
preferably displays the location of the guide relative to the
adjacent vertebrae to provide a view of the axial orientation of
the guide relative to each vertebra and/or relative to the adjacent
vertebrae. The generating step may also display the location of the
guide relative to the adjacent vertebrae to provide a
cross-sectional view of the guide relative to one of an anterior or
posterior view of the adjacent vertebrae. The generating step may
also display the location of the guide relative to the adjacent
vertebrae to provide a cross-sectional view of the guide in the
sagittal and coronal planes or in planes relative to the current
trajectory of the guide.
The method may also include the step of emitting a signal from an
emitter attached to the guide which is received by an apparatus
representatively indicating that signal on a visual display. A
preferred method of the present invention also includes the step of
implanting one of an artificial implant and a bone dowel into the
implantation space.
It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
and in construction of this guide in association with a surgical
navigation system without departing from the scope or spirit of the
invention. Other embodiments of the invention will be apparent to
those skilled in the art from consideration of the specification
and practice of the invention disclosed herein. It is intended that
the specification and examples be considered as exemplary only.
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